In continuation of a project on the chemical fine structure of lung heparinoid polysaccharides, it is proposed to perfect high pressure liquid chromatography techniques for separation and for analysis of the oligosaccharides derivable from beef lung heparin by deaminative degradation and further chemical manipulation. Isolation and characterization of six reference disaaccharides and of some tetrasaccharides has been completed. The isolation and structural diagnosis of additional tetrasaccharides is planned. From the tetrasaccharides, the preparation of characterized trisaccharides by chemical and enzymatic manipulation will be undertaken. Purification from beef liver of alpha-L-iduronidase, the principal enzyme required for this purpose, forms part of this program.